The present invention relates to a waste toner recovery unit for recovering waste toner.
Generally, an image forming apparatus is provided with a waste toner recovery unit for recovering waste toner which has been deteriorated after being used at a transfer process. This type of waste toner recovery unit is detachably installed to the image forming apparatus body, and, when the amount of toner which has been recovered has reached a certain constant amount and when maintenance is being performed, the waste toner recovery unit is removed from the image forming apparatus body and exchanged.
Some waste toner recovery units are provided with a waste toner recovery container and a rotary type shutter for switching between an opened state and a closed state of a waste toner discharge port of the image forming apparatus body. That is to say, by switching a position of the rotary type shutter from a closed position to an opened position, the waste toner discharge port and the waste toner recovery container of the image forming apparatus body are brought into communication with each other, and guide the waste toner conveyed from the image forming apparatus body to the inside of the waste toner recovery container.
In recent years, a structure has been developed for switching between an opened state and a closed state by manual rotation of an inside cylinder in a part called a joint portion where the inside cylinder in which a waste toner discharge port is formed in an outer peripheral surface thereof is rotatably incorporated into the inside of an outside cylinder in which a toner discharge port is formed in an outer peripheral surface thereof and which is placed in a fixed position (refer to Patent Document 1: Japanese Patent Laid-Open Publication No. 2001-249594, for example). In this structure, a waste toner recovery unit without occurrence of leakage of waste toner at such a joint portion and with excellence in operability can be obtained.
However, the Patent Document 1 does not disclose the structure described in the Patent Document 1 causes deterioration in operability accompanying torque increase when the rotary type shutter is rotated due to the effects such as a toner clog in the joint portion between the image forming apparatus body and the rotary type shutter. That is, in the end surface at a base end in which the rotary type shutter is connected to the image forming apparatus body, a toner clog occurs as the duration of use of the image forming apparatus body becomes longer, thereby increasing torque in rotating the rotary type shutter for switching between an opened state and an closed state and causing the deterioration of operability.
In view of the foregoing problems, it is an object of the present invention to provide a waste toner recovery unit capable of preventing the operability from being deteriorated even by the use over a long period of time.